The present invention relates in general to an under-bed fifth wheel hitch mounting system used to removable secure items such as a fifth wheel hitch to a vehicle.
Fifth wheel and gooseneck hitch mounting systems are well known for use with the cargo bed area of pickup trucks and related vehicles. However, such mounting systems are typically bolted to the under frame of the vehicle through the use of essentially permanent fastener systems such as bolt and nut combinations, wherein the nut passes through the hitch mounting system, through the cargo bed area floor and into the under frame.
Such a permanent mounting system is highly undesirable. In particular, the hitch mounting system is typically not used on a regular basis, but only when towing a specialized trailer requiring such a system. A permanent mounting system greatly reduces the total cargo volume available for daily usage when the hitch is not required. Additionally, the mounting system is typically unsightly, reducing the ascetic appeal of the vehicle. Further, by having a permanent connection, corrosion can take place over time, making even a desired removal of a hitch nearly impossible.
To solve the problem of typical above-bed hitch mounting systems, an attempt has been made to develop an under-bed system 10 as illustrated in prior art FIG. 1. System 10 relies on the use of a solid cylindrical pin 12 received in a mating opening 14 provided in an under-bed tube 16 extending generally perpendicular to the longitudinal axis of the opening. Pin 12 includes opposed upper end 18 and lower end 20, a permanent washer 22 attached to pin 12 adjacent to upper end 18. A thin rod 24 extends perpendicularly from an outer surface 26 of the pin. Receptacle 14 includes a base portion 28 with two opposing channels 30 extending radially outwardly from the base portion 28, each of which are sized to receive rod 24 when pin 12 is properly positioned and inserted into receptacle 14. The pin is then twisted such that the rod 24 is no longer aligned with a channel 30.
In operation, the use of pin 12 is less than ideal. A key problem is noise since the pin has a tendency to move up and down during vehicle usage, resulting in a disconcerting and loud banging or rattling. Further, as the pin rattles, it exhibits an undesirable tendency to rotate, possibly resulting in the accidental alignment of the rod 24 with a channel 30. If such an alignment takes place, hitch-mounting components secured between pin 12 and under-bed tube 16 may be undesirably released. Finally, since the pin is free to move up and down, when sudden and heavy loads are applied, the pin may be moved at high speed towards the underside of tube 16, and could snap under the impact.
The disclosed invention is directed to an easily removable hitch locking mechanism comprising a male pin and a female receptacle. The receptacle and the necessary structure to support the receptacle are placed under the cargo bed floor of a vehicle. The receptacle is constructed such that when it is not in use, the cargo bed floor may be used in a traditional manner. However, when a fifth wheel hitch system or the like must be installed, the pins may be inserted through a component to be secured and inserted into a mating receptacle. The pin includes a groove comprising a stem and base such that when the pin is properly installed within the receptacle, it does not move longitudinally, laterally, or spin with respect to the receptacle unless purposely unlocked, thus providing a strong, rigid connection point for the secured component. The pin may be easily removed when the component is no longer required and the cargo bed returned to its normal operational status. When pins and mating receptacles are used, however, the resulting structure is very rigid and secure, providing appropriate loading support to secured components such as those comprising a fifth wheel hitch or a tie down. Moreover, the nature of the connection between the pins and receptacles eliminates undesirable noise even under changing or extreme load conditions.
A first embodiment of the invention is directed to a twistable lock pin. The pin includes a cone shaped first end and a pivotable handle at a second end. A center portion is disposed between the first end and the second end. A generally L-shaped groove is disposed along the outer circumference of the center portion. A stem of the groove intersects the first end and extends along the center portion to terminate at a base adjacent the second end. The base is generally perpendicular to the stem. However, in a preferred embodiment of the invention, the angle between the stem and the base is slightly greater than ninety degrees to promote a firm connection of the pin within its receptacle.
The receptacle of the first embodiment is a tubular socket including a rod extending from an inner periphery of the socket wall that matingly engages the groove stem. When the pin is properly inserted into the socket, the rod engages the groove stem, providing an entry path to the groove base. The handle of the lock pin is then rotated approximately a quarter turn to lock it in the socket, the rod moving up the base. Ideally, the positioning of the groove base with respect to the second end is selected such that the second end is at least closely adjacent to the upper surface of the socket. A notch may be used within the base to further help secure the rod within the base, the rod engaging the notch at a final locked position, thereby further minimizing the possibility of the pin undergoing unintentional rotation within a mating receptacle. To unlock the pin from the receptacle, the pin is raised or lowered, depending on the relative location of the notch. The longitudinal movement disengages the rod of the socket from the pin base, and then the pin is twisted toward an unlocked position. Alternatively or in addition to the use of a notch, the use of compressible elastomeric material between the pin and the receptacle may also be desirable to help provide appropriate biasing and a more secure connection for the component secured between the pin and the receptacle.
A second embodiment of the invention uses a different type of pin and receptacle combination acting as a locking mechanism to retain a component. However, the pin still includes a groove with a stem and a base that engages the receptacle. The pin is a scissor clamp with opposing jaws pivotable about a common hinge between an unlocked installation position and a locked component retention position. Each of the jaws includes a terminating end with a ledge acting as the base and a mating component portion at an opposite end. The stem of the groove is disposed between the base and the mating component portion. The receptacle receives the terminating end of the clamp, both the base and the stem engaging the receptacle to limit lateral, longitudinal, and rotational movements of the pin.
To prevent the clamp from improperly opening, an adjustable fastener such as a nut and bolt arrangement is illustrated. When the fastener is loosened, the clamp can be opened and closed. When the fastener is tightened, the clamp is secured in its closed position. Typically, using the adjustable fastener, one of the jaws moves with respect to the other jaw.